mine wrote:
The whole rationale based on Cooper having a hero complex has one huge weak point. Cooper did barely anything heroic out of his own nature alone. He was always put on that path by either the people who wanted to be saved by him, the FBI when it comes to Laura's case or the entities from the surreal realm when it comes to whatever their machinations were. Even in retrospect Cooper trying to dissuade Laura from taking the ring is consistent with the notion that he was following The Fireman's instructions because whatever Laura was the chosen one for, she needed to be alive to fulfill her destiny (she just needed a dude to guide her, because hey it's Twin Peaks) which is what the finale was all about.
There is a better argument to be made that he is at the core a tropy super hero character. He doesn't always conclude his missions successfully, but so doesn't every super hero ever at some point.
The ring has always been a bit of an enigma, though to me there's a simpler and relatively innocent explanation for Cooper warning Laura not to take it: The Arm is the one offering it to her. Cooper has just learned that The Arm is, well, The Arm, and he knows that Philip/MIKE lost his arm when making his break with BOB. So he probably puts 2 and 2 together and figures that The Arm represents the more malevolent aspect of MIKE's personality and should not be trusted.
I'm not sure that Cooper's problem is exactly a hero complex so much as thinking he has more understanding and control of the supernatural forces at work than he actually does. The fact that The Fireman alluded to Richard and Linda and 430 doesn't mean that he was actually telling Cooper to "cross over," or that Cooper would necessarily understand what's supposed to happen after crossing over even if that was the Fireman's intention. Maybe he was never meant to find "Carrie" or take her to Twin Peaks and Laura was trying to warn him *not* to do that when she told him "I am dead, yet I live."
As Cooper himself said, the shortest distance between two points is not necessarily a straight line. Involve the Lodge spirits, and the shortest distance between two points may well be a ten-dimensional M.C. Escher drawing.